Nekojiru-sou

Both follow a traveler, both have a particular atmosphere, and an original design. 

Cat Soup and Kaiba both have a surreal, whimsical quality to their story, characters and animation. Their worlds are both wildly imaginative and fantastic, but a solid realization of the characters and their circumstances keep them grounded and engaging. 

Made from the same director Masaaki Yuasa, these are both filled symbolism and philosophy but have different approaches to it. Kaiba is to memories as Cat Soup is to souls and destiny. Production values are excellent. 

Both share surreal visual themes, and both convey mature ideas using a simple art style reminiscent of children's cartoons. Further, Masaaki Yuasa was a significant creative contributor on both works. 

Both are very surrealistic, Psychological, ripe with symbolism and metaphor, rich in philosophy and filled with abstract idea's relating to our existence, life and the world around us. 

Similar eerie, yet calming atmosphere, little dialogue, and the events that take place are left to the viewer's interpretation. 

Both are relatively short, bleak movies that contain very little dialogue. They both have a dark and surreal atmosphere, with imagery that seems to have many metaphorical and nearly unperceptible meanings. In other words, you won't find much of a coherent story here, and if you do, it probably won't be the same story that other viewers get. 

- Surrealism. - Nyatta want to save Nyako's soul, Boy want to save Girl's soul. - "A small fish in a big pond" kind of story. Both world are so vast and ever-expanding. 

Happy Machine is similar to this OVA. Bunch of absurd things happening. 

Masaaki Yuasa directed the sixth short of "Genius Party", "Happy Machine", and before that was envolved in the creation of "Cat Soup". Thus, both of them presents a surrealist animation with a strange and uniquel history, where dialogues do not exist and are not necessary. 

Creativy, metaphors, surrealism and originality are what both these series are all about! These are short anime about completely abstract and mind-blowing adventures, in which you have to focus on every second not to miss that surreal beauty, and to understand at least anything. In Genius Party half of the episodes are made in that manner, and Nekojiru-sou is a short film which doesn't wander off its weirdness even for a moment. What's more, one of the directors of GP, Masaaki Yuasa, is also a screenwriter and animation director for Nekojiru-sou! 

Both of these are short, dark, expressive animations. 

Both shows are dark and slaps out that avant garde genere.  

Very weird shows, with unconventional art styles that just add to the creepiness of their confusing storylines.  

Both features anthropomorphic kittens having a travel to a surreal world. 

Nekojiru-sou also stars a cast of anthropomorphic cats that go on a surreal adventure. Both feature films have darker undertones than at first glance. The art style is also otherworldly and is sure to remind the audience of Ginga Tetsudou no Yoru.  

Both movies are about antrophomorpic cats traveling a surreal land and meeting odd people there. Both are packed with religious symbolism, Nekojiru-sou with several religions, Ginga with only Christianity. Both have dream-like athmosphere and use a lot of symbolism open to interpretation (Ginga is more heavy handed at it). In both, one of the protagonists may be dead and they may be in an afterlife world. 

Both are really weird Dementia anime featuring animated cats. 

Experimental anime with atypical artstyle and animation that features some disturbing and surreal (but interesting) imaginery. 

Both have surreal, dream-like story where you have to think really hard to get what happened. Nekojiro-sou is more surreal. 

Both take place in very surreal worlds. Both are also up to the viewers interpretation mostly. Also both are very surreal and have amazing art 

Both have abstract and seemingly disconnected scenes in a surreal and dreamlike atmosphere, but each tie up to a central theme by the end. The visuals defy reality and are extremely bizarre, yet are whimsical and beautiful at the same time. Both have music made by Utollo Teshikai/Hiroshi Ogasawara (same person) which contributes greatly to their unique atmospheric characteristics.  

they are very similar in the way the story unfolds, lots of mystery 

Nekojiru-sou and the first episode of Manie-Manie, Labyrinth Labyrinthos, both involve cats and a circus performance, with a similar and expressive animation where characters are constantly getting deformed. Nekojiru-sou is also darker and gory, something that can be found in the second episode of Manie-Manie, Running Man. 

Both explore a surrealistic world. 

Bizarre movies that make little to no sense. Cat Soup has a meaning, though. 

An unearthly distortion in the works. An unsettling collection of things that live and move like us, but very wrong so at that. Whatever these creatures have in mind, follows no world like our own. Countless seconds munching away at this paranormal dystopia of a surreal reality, that you have a chance to view. 

Both are extremely bizarre psychological anime that are extremely similar in tone and delivery 

Sometimes things are made and you ask, why? I have no answer, but do you even need an answer? Welcome to the "what the hell" side of art starring nonsensical adventure Cat Soup and kill-it-with-fire Striking Daughter. Truly unorthodox pieces of art.